U.S. patent application number 13/010555 was filed with the patent office on 2011-07-28 for method and device for treatment of keloids and hypertrophic scars using focused ultrasound.
This patent application is currently assigned to SLENDER MEDICAL LTD.. Invention is credited to Haim Azhari, Solli Brawer, Liat Tsoref.
Application Number | 20110184322 13/010555 |
Document ID | / |
Family ID | 44309489 |
Filed Date | 2011-07-28 |
United States Patent
Application |
20110184322 |
Kind Code |
A1 |
Brawer; Solli ; et
al. |
July 28, 2011 |
METHOD AND DEVICE FOR TREATMENT OF KELOIDS AND HYPERTROPHIC SCARS
USING FOCUSED ULTRASOUND
Abstract
A method for treating a scar on a skin surface of a subject is
provided. A subject is identified as having a skin surface with
scar tissue. In response to identifying the subject as having the
scar tissue, a housing comprising at least one acoustic transducer
is placed on the skin surface with the scar tissue and the acoustic
transducer is activated to apply high intensity focused ultrasound
energy to a portion of the scar tissue. Other embodiments are also
described.
Inventors: |
Brawer; Solli; (Kiryat Ono,
IL) ; Azhari; Haim; (Doar-Na Misgav, IL) ;
Tsoref; Liat; (Tel Aviv, IL) |
Assignee: |
SLENDER MEDICAL LTD.
Herzliya
IL
|
Family ID: |
44309489 |
Appl. No.: |
13/010555 |
Filed: |
January 20, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61297286 |
Jan 22, 2010 |
|
|
|
Current U.S.
Class: |
601/3 |
Current CPC
Class: |
A61B 2018/00023
20130101; A61B 2017/00084 20130101; A61N 2007/0078 20130101; A61N
2007/0091 20130101; A61N 2007/0069 20130101; A61N 2007/0034
20130101; A61N 7/02 20130101; A61B 2017/00106 20130101 |
Class at
Publication: |
601/3 |
International
Class: |
A61N 7/00 20060101
A61N007/00 |
Claims
1. A method for treating a scar on a skin surface of a subject, the
method comprising: identifying a subject as having a skin surface
with scar tissue; in response to identifying the subject as having
the scar tissue, placing a housing comprising at least one acoustic
transducer on the skin surface with the scar tissue; and activating
the acoustic transducer to apply high intensity focused ultrasound
energy to a portion of the scar tissue.
2. The method according to claim 1, wherein the scar tissue
includes a hypertrophic scar, and wherein applying high intensity
focused ultrasound energy to the scar tissue comprises applying
high intensity focused ultrasound energy to the hypertrophic
scar.
3. The method according to claim 1, wherein the scar tissue
includes a keloid scar, and wherein applying high intensity focused
ultrasound energy to the scar tissue comprises applying high
intensity focused ultrasound energy to the keloid scar.
4. The method according to claim 1, wherein activating the acoustic
transducer to apply high intensity focused ultrasound energy to the
scar tissue comprises elevating the temperature of the scar
tissue.
5. The method according to claim 4, wherein elevating the
temperature of the scar tissue comprises elevating the temperature
to at least 57 C.
6. The method according to claim 1, wherein activating the acoustic
transducer to apply high intensity focused ultrasound energy to the
scar tissue comprises inducing cavitation of the scar tissue.
7. The method according to claim 1, wherein the housing includes a
cooling fluid and wherein the method further comprises cooling the
skin surface with the cooling fluid.
8. The method according to claim 7, wherein the cooling fluid
includes liquid nitrogen, and wherein cooling comprises cooling the
skin surface with the liquid nitrogen.
9. The method according to claim 1, further comprising suctioning
treated tissue following application of high intensity focused
ultrasound energy to the scar tissue.
10. The method according to claim 1, further comprising
repositioning the acoustic transducer following activation of the
acoustic transducer, and subsequently to the repositioning,
activating the acoustic transducer to apply high intensity focused
ultrasound energy to another portion of the scar tissue.
11. A method for treating a scar on a skin surface of a subject,
the method comprising: identifying a subject as having a skin
surface with scar tissue; in response to identifying the subject as
having the scar tissue, clamping a portion of the scar tissue using
at least one acoustic transducer; and activating the at least one
acoustic transducer to apply high intensity focused ultrasound
energy to the portion of the scar tissue.
12. The method according to claim 11, further comprising reflecting
the transmitted energy from the acoustic transducer toward the scar
tissue with an acoustic reflector.
13. The method according to claim 11, wherein the scar tissue
includes a hypertrophic scar, and wherein applying high intensity
focused ultrasound energy to the scar tissue comprises applying
high intensity focused ultrasound energy to the hypertrophic
scar.
14. The method according to claim 11, wherein the scar tissue
includes a keloid scar, and wherein applying high intensity focused
ultrasound energy to the scar tissue comprises applying high
intensity focused ultrasound energy to the keloid scar.
15. The method according to claim 11, wherein activating the
acoustic transducer to apply high intensity focused ultrasound
energy to the scar tissue comprises elevating the temperature of
the scar tissue.
16. The method according to claim 15, wherein elevating the
temperature of the scar tissue, comprises elevating the temperature
to at least 57 C.
17. The method according to claim 11, wherein activating the
acoustic transducer to apply high intensity focused ultrasound
energy to the scar tissue comprises inducing cavitation of the scar
tissue.
18-28. (canceled)
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims the priority of U.S.
Provisional Application 61/297,286 to Brawer, entitled, "Method and
device for treatment of keloids and hypertrophic scars using
focused ultrasound," filed Jan. 22, 2010, which is incorporated
herein by reference.
FIELD OF THE APPLICATION
[0002] The present invention relates generally to treatment of
scars and particularly to methods and apparatus for treatment of
hypertrophic scars and keloids, by application of focused
ultrasound energy thereto.
BACKGROUND OF THE APPLICATION
[0003] Wound healing in certain individuals may lead to the
development of hypertrophic scars and/or keloids. Hypertrophic
scars typically take the form of a raised scar on the skin, and
occur due to excessive production of collagen during a wound
healing process. Hypertrophic scars typically do not grow beyond
the boundaries of the original wound area.
[0004] In contrast, keloids, or keloidal scars, expand beyond the
original wound site and may grow into a firm lump that is many
times larger than the original scar. Keloids are typically fibrotic
growths that contain a collection of atypical fibroblasts and an
increased abundance of extracellular matrix components, especially
collagen.
[0005] Although commonly benign, hypertrophic scars and keloids
often cause discomfort, pain, pruritus, physical disfigurement and
impaired quality of life.
[0006] Current approaches for treatment of hypertrophic scars
and/or keloids include silicone devices for applying local
pressure, injection of various materials (e.g. steroids, verapamil,
5-FU, etc.), freezing the tissue with liquid nitrogen, laser
ablation, surgical removal and ionizing radiation.
SUMMARY OF APPLICATIONS
[0007] In some applications of the present invention, a method and
apparatus for treating scar tissue on a skin surface of a subject
are provided. Typically, a subject is identified as having a skin
surface with scar tissue. For some applications, the scar tissue
includes a hypertrophic scar and/or a keloid scar. In response to
identifying the subject as having the scar, a housing comprising at
least one acoustic transducer, e.g., an ultrasound transducer, is
placed on the skin surface with the scar tissue. The ultrasound
transducer is activated to apply high intensity focused ultrasound
(HIFU) energy to the scar tissue. Application of high intensity
focused ultrasound energy to the scar tissue typically leads to
elevation of the temperature within the scar tissue.
[0008] As described hereinabove, the hypertrophic and/or keloid
scar tissue contains an accumulation of collagen. Elevation of the
temperature within the scar tissue to a critical temperature
typically results in heat-induced changes in the collagen, e.g.,
denaturing of collagen molecules typically when the temperature is
raised to or above 60 C. Thermal denaturing of collagen generally
occurs by the dissociation of heat-sensitive bonds of the collagen
molecule and may result in denaturing of collagen into gelatin as
described in an article by Harel A et al., entitled, "Magnetization
transfer based contrast for imaging denatured collagen" J Magn
Reson Imaging. 2008 May; 27(5):1155-63, which is incorporated
herein by reference. As provided by some applications of the
present invention, the focused ultrasound energy that is applied to
the scar tissue is capable of elevating the temperature within the
scar tissue to a temperature that is sufficient to cause denaturing
of collagen within the scar tissue. For some applications, heating
of the scar tissue results in denaturing the collagen into gelatin.
The gelatin is typically softer than collagen, and thus may relieve
discomfort, pain, pruritus and/or physical disfigurement that are
associated with the scar tissue. Additionally, softer, gelatin
containing scar tissue, may be easily removed.
[0009] For some applications, following application of high
intensity focused ultrasound energy to the scar tissue, a suction
device is applied to remove treated scar tissue from the skin. For
applications in which elevation of the temperature within the scar
tissue leads to collagen denaturating to gelatin, the gelatin is
removed from the scar tissue.
[0010] Additionally or alternatively, elevation of the temperature
within the scar tissue by use of high intensity focused ultrasound
energy results in destruction of collagen-producing fibroblast
cells within the scar tissue, thereby reducing further production
of collagen.
[0011] There is therefore provided, in accordance with some
applications of the present invention, a method for treating a scar
on a skin surface of a subject, the method including: [0012]
identifying a subject as having a skin surface with scar
tissue;
[0013] in response to identifying the subject as having the scar
tissue, placing a housing including at least one acoustic
transducer on the skin surface with the scar tissue; and
[0014] activating the acoustic transducer to apply high intensity
focused ultrasound energy to a portion of the scar tissue.
[0015] For some applications, the scar tissue includes a
hypertrophic scar, and applying high intensity focused ultrasound
energy to the scar tissue includes applying high intensity focused
ultrasound energy to the hypertrophic scar.
[0016] For some applications, the scar tissue includes a keloid
scar, and applying high intensity focused ultrasound energy to the
scar tissue includes applying high intensity focused ultrasound
energy to the keloid scar.
[0017] For some applications, activating the acoustic transducer to
apply high intensity focused ultrasound energy to the scar tissue
includes elevating the temperature of the scar tissue.
[0018] For some applications, elevating the temperature of the scar
tissue includes elevating the temperature to at least 57 C.
[0019] For some applications, activating the acoustic transducer to
apply high intensity focused ultrasound energy to the scar tissue
includes inducing cavitation of the scar tissue.
[0020] For some applications, the housing includes a cooling fluid
and the method further includes cooling the skin surface with the
cooling fluid.
[0021] For some applications, the cooling fluid includes liquid
nitrogen, and cooling includes cooling the skin surface with the
liquid nitrogen.
[0022] For some applications the method includes, suctioning
treated tissue following application of high intensity focused
ultrasound energy to the scar tissue.
[0023] For some applications the method includes, repositioning the
acoustic transducer following activation of the acoustic
transducer, and subsequently to the repositioning, activating the
acoustic transducer to apply high intensity focused ultrasound
energy to another portion of the scar tissue.
[0024] There is further provided, in accordance with some
applications of the present invention, a method for treating a scar
on a skin surface of a subject, the method including:
[0025] identifying a subject as having a skin surface with scar
tissue;
[0026] in response to identifying the subject as having the scar
tissue, clamping a portion of the scar tissue using at least one
acoustic transducer; and
[0027] activating the at least one acoustic transducer to apply
high intensity focused ultrasound energy to the portion of the scar
tissue.
[0028] For some applications the method includes, reflecting the
transmitted energy from the acoustic transducer toward the scar
tissue with an acoustic reflector.
[0029] For some applications, the scar tissue includes a
hypertrophic scar, and applying high intensity focused ultrasound
energy to the scar tissue includes applying high intensity focused
ultrasound energy to the hypertrophic scar.
[0030] For some applications, the scar tissue includes a keloid
scar, and applying high intensity focused ultrasound energy to the
scar tissue includes applying high intensity focused ultrasound
energy to the keloid scar.
[0031] For some applications, activating the acoustic transducer to
apply high intensity focused ultrasound energy to the scar tissue
includes elevating the temperature of the scar tissue.
[0032] For some applications, elevating the temperature of the scar
tissue, includes elevating the temperature to at least 57 C.
[0033] For some applications, activating the acoustic transducer to
apply high intensity focused ultrasound energy to the scar tissue
includes inducing cavitation of the scar tissue.
[0034] There is still further provided, in accordance with some
applications of the present invention, apparatus including:
[0035] a housing adapted for placement on a skin surface with scar
tissue;
[0036] at least one acoustic transducer coupled to the housing and
configured to apply high intensity focused ultrasound energy to
portion of the scar tissue; and
[0037] a liquid nitrogen cooling fluid surrounding the acoustic
transducer.
[0038] There is yet additionally provided, in accordance with some
applications of the present invention, apparatus including:
[0039] a housing adapted for placement on a skin surface with scar
tissue;
[0040] at least one acoustic transducer coupled to the housing and
configured to apply high intensity focused ultrasound energy to a
portion of the scar tissue for treatment of the scar tissue;
and
[0041] a suction device configured to remove the treated scar
tissue following treatment.
[0042] For some applications the apparatus includes, a sensing
element configured to generate a signal that activates the suction
device.
[0043] For some applications, the sensing element includes a
temperature sensor configured to sense a temperature of the scar
tissue, and, in response, activate the suction device.
[0044] For some applications, the scar tissue includes a
hypertrophic scar, and the at least one acoustic transducer is
configured to apply high intensity focused ultrasound energy to the
hypertrophic scar.
[0045] For some applications, the scar tissue includes a keloid
scar, and the at least one acoustic transducer is configured to
apply high intensity focused ultrasound energy to the keloid
scar.
[0046] For some applications, the at least one acoustic transducer
is configured to apply high intensity focused ultrasound energy to
the scar tissue to elevate the temperature of the scar tissue.
[0047] For some applications, the at least one acoustic transducer
is configured to elevate the temperature of the scar tissue to at
least 57 C.
[0048] For some applications, the housing includes a cooling fluid
configured to cool the skin surface.
[0049] For some applications, the cooling fluid includes liquid
nitrogen.
[0050] For some applications, the housing includes a base portion
that is transparent to ultrasound waves and has high thermal
conductivity.
[0051] The present invention will be more fully understood from the
following detailed description of applications thereof, taken
together with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] FIG. 1 is a schematic illustration of apparatus and a method
for treating scar tissue on a skin surface of a subject, in
accordance with some applications of the present invention;
[0053] FIG. 2 is a schematic illustration of an ultrasound
transducer for treatment of scar tissue, and a suction device
operable in combination with the ultrasound transducer, in
accordance with some applications of the present invention;
[0054] FIG. 3 is a schematic illustration of apparatus for
treatment of scar tissue, in accordance with some applications of
the present invention; and
[0055] FIGS. 4A-B are schematic illustrations of configurations of
the apparatus for treating scar tissue, positioned in contact with
the scar tissue, in accordance with some applications of the
present invention.
DETAILED DESCRIPTION OF APPLICATIONS
[0056] FIG. 1 is a schematic illustration of an apparatus and
method for treating scar tissue on a skin surface of a subject by
application of focused ultrasound energy thereto, in accordance
with some applications of the present invention. For some
applications, the scar tissue includes a hypertrophic scar and/or a
keloid scar.
[0057] For some applications, apparatus 10 is provided for the
treatment of scar tissue 30, e.g., a hypertrophic scar and/or a
keloid scar. Typically, apparatus 10 comprises a housing 40
comprising at least one ultrasound transducer 20. Apparatus 10 is
configured for placement on scar tissue on a skin surface of a
subject. Ultrasound transducer 20 is configured to apply high
intensity focused ultrasound energy to the scar tissue for
treatment, e.g., removal and/or reduction, of the scar tissue.
[0058] Apparatus 10 is typically used with a suitable acoustic
coupling fluid. Additionally, housing 40 comprises a base portion
45, which is typically transparent to ultrasound waves yet has high
thermal conductivity. For some applications, base portion 45
comprises a thin membrane composed of a polyether film. Apparatus
10 is typically configured to focus energy transmission to a
particular area of the scar tissue in order to enable treatment at
a desired focal zone 70. Typically, focal zone 70 is located
several millimeters under the base portion, for example 1-15 mm
from the base portion.
[0059] For some applications, apparatus 10 applies high intensity
focused ultrasound to scar tissue 30 at a frequency of 0.5-10 MHz,
e.g., 2-5 MHz. Application of high intensity focused ultrasound
energy to scar tissue 30 typically leads to a rapid rise in
temperature within the scar tissue, typically to a temperature that
is higher than 57 C, e.g. 58-80 C, e.g. 58-70 C. The treated scar
tissue is thus ablated as a result of the rise in temperature, and
is typically naturally removed by the body during the weeks
following the treatment. For some applications, apparatus 10 is
configured to apply lower frequencies, e.g. frequencies of 50-500
kHz. Application of energy in such frequencies, typically in
combination with pulse sequences having a duty cycle which is less
than 20% may create an effect of cavitation in the scar tissue and
consequently, lead to destruction of the scar tissue. It is to be
noted that techniques described with reference to creating
cavitation in PCT Publication WO 2000-53263 to Rosenschein, may be
practiced in combination with techniques described herein.
[0060] Additionally or alternatively, elevation of the temperature
within the scar tissue results in heat-induced denaturing of
collagen in the scar tissue. For some applications, heating of the
scar tissue results in denaturing of the collagen into gelatin. The
gelatin is typically softer than collagen, and thus may relieve
discomfort, pain, pruritus and/or physical disfigurement that are
associated with the scar tissue. Additionally, softer,
gelatin-containing scar tissue may be easily removed. Further
additionally, elevation of the temperature within the scar tissue
by use of high intensity focused ultrasound energy may result in
destruction of collagen-producing fibroblast cells within the scar
tissue, thereby reducing further production of collagen.
[0061] For some applications, the ultrasound energy emitted from
transducer 20 is focused such that focal zone 70 is disposed
beneath the surface of the skin containing the scar, so as to
reduce or avoid damage to the surface of the skin. Ultrasound
transducer 20 is typically surrounded by a cooling fluid that flows
through housing 40 in proximity to the skin surface and removes
excess heat from transducer 20 and/or from the surface of the skin.
Thus, apparatus 10 is configured to simultaneously heat a desired
area in scar tissue 30, while preventing heating of other areas of
the scar tissue as well as adjacent skin surface and tissue areas.
Typically, the area above the dashed line in scar tissue 30, shown
in FIG. 1, is generally not heated as a result of the high
intensity focused ultrasound applied to scar tissue 30.
[0062] For some applications, the cooling fluid comprises a very
low temperature cooling fluid, such as liquid nitrogen, which is
kept close to the freezing temperature of the fluid (e.g., 63-70
K), in order to maintain the skin surface at a very low
temperature. For these applications, housing 40 typically comprises
a base portion 45, which is typically transparent to ultrasound
waves yet has high thermal conductivity.
[0063] For some applications, the skin surface and adjacent tissue
may be frozen, e.g., by being brought to a temperature of 0-10 C.
Lowering the temperature of the skin surface and tissue in the
vicinity of the heated focal zone may reduce the occurrence of
damage to the skin, e.g., skin burns, as a result of thermal
treatment of the skin containing scar tissue 30. Additionally or
alternately, if freezing is achieved and sustained for adequate
time, non-invasive tissue destruction of the skin and the tissue
layers proximal to it is achieved. This may lead to skin
rejuvenation and better cosmetic effect.
[0064] It is to be noted that for some applications, apparatus 10
does not use a cooling fluid.
[0065] Reference is made to FIG. 2 which is a schematic
illustration of an ultrasound transducer 20 for treatment of scar
tissue 30, and a suction device 80 operable in combination with the
ultrasound transducer, in accordance with some applications of the
present invention. As described hereinabove with reference to FIG.
1, apparatus 10 applies high intensity focused ultrasound energy to
scar tissue 30, leading to a rise in temperature within the scar
tissue, typically to a temperature that is higher than 57 C, e.g.
58-80 C, e.g. 58-70 C. This thermal treatment of tissue 30
typically results in destructions of cells, e.g., fibroblast cells,
and other components of the scar tissue. Additionally or
alternatively, the elevation of temperature in scar tissue 30 leads
to thermally-induced changes in collagen, e.g., denaturing of
collagen into gelatin. Therefore, thermal treatment of the scar
tissue yields a softer, more fluid, tissue which can be removed by
suction device 80. Additionally or alternatively, cell debris may
be removed following treatment of the scar tissue. For some
applications, subsequently to or simultaneously with application of
the ultrasound energy to the scar tissue, suction device 80 is
operated in order to remove the treated tissue.
[0066] Typically, suction device 80 comprises a needle 90, at a
distal end thereof. Needle 90 is typically inserted into scar
tissue 30, in a vicinity of focal zone 70. Suction device 80 is
operated to remove the treated scar tissue through needle 90.
Needle 90 may be inserted into scar tissue 30 at any stage prior
to, during, or following treatment of scar tissue 30.
[0067] The apparatus may comprise a sensing element configured to
generate a signal that activates suction device 80. For some
applications, needle 90 comprises the sensing element. Typically,
the sensing element is configured to sense a temperature of the
scar tissue and generate a signal for activation of suction device
80 when the scar tissue reaches a temperature that is sufficient
for converting the scar tissue into a softer, more fluid tissue,
e.g., 60 C. For such applications, needle 90 is inserted into scar
tissue 30 prior to or during treatment of the scar tissue.
Application of the focused ultrasound to scar tissue 30 causes a
rise in temperature within the scar tissue triggering activation of
suction device 80 when the scar tissue reaches a desired
temperature.
[0068] Additionally or alternatively, ultrasound transducer 20 is
configured, in addition to applying high intensity treatment
energy, to transmit short low intensity ultrasound pulses and
receive their echo. The received echo signals may be analyzed to
detect a change in the fluidity of the scar tissue that typically
occurs as a result of thermal treatment to the tissue, and in
response, to terminate application of the high intensity treatment
energy and/or to activate suction device 80.
[0069] Reference is made to FIG. 3, which is a schematic
illustration of apparatus for treatment of scar tissue 30, in
accordance with some applications of the present invention. For
some applications, housing 40 as described with reference to FIGS.
1-2 is configured to house more than one ultrasound transducer 20.
FIG. 3 shows housing 40a comprising more than one transducer 20.
FIG. 3 shows housing 40a comprising two ultrasound transducers, 20a
and 20b, by way of illustration and not limitation. Housing 40a may
comprise any suitable number of ultrasound transducers 20.
Typically, transducers 20a and 20b are confocal transducers, having
substantially the same focal zone 70. Transducers 20a and 20b are
configured to simultaneously or alternately apply high intensity
focused energy for treatment, by heating and/or inducing cavitation
of scar tissue 30, as described herein.
[0070] For some applications, e.g., at predetermined time
intervals, one of transducers 20a or 20b may function as a receiver
for detecting scattered waves from the treatment area, in the
vicinity of focal zone 70, while the other transducer continues to
apply treatment energy. The detected waves may be analyzed and used
for monitoring changes in the scar tissue as a result of the
treatment process, by measuring parameters such as scatter
intensity, attenuation, speed of sound, non-linear parameters, sub
harmonics and second harmonic reflections, thus allowing
non-invasive monitoring of the treatment process.
[0071] Reference is made to FIGS. 1-3. For some applications, any
transducer 20 (i.e., transducer 20, 20a and 20b) may be steered,
rotated, or moved over the skin, in order to change the location of
focal zone 70. Such movements of transducer 20 typically allow
treatment of a larger area of scar tissue 30 (see dashed focal
zones 70 in FIG. 2). For some applications, steering of transducer
20 is performed by a robotic mechanism that is coupled to
transducer 20. Any other suitable steering mechanism may be
used.
[0072] Reference is made to FIGS. 4A-B, which are schematic
illustrations of configurations of apparatus 100 for treating scar
tissue, positioned in contact with the scar tissue, in accordance
with some applications of the present invention. Some or all
apparatus and methods described hereinabove with reference to FIGS.
1-3 are typically utilized with the embodiments shown in FIGS.
4A-B, except with differences as described below.
[0073] For some applications, apparatus 100 comprises a housing
400, which typically comprises first and second clamping elements
50, which are configured to clamp a portion of scar tissue 30
therebetween. Typically, confocal ultrasound transducers 200a and
200b are coupled to clamping elements 50 and are configured to
transmit focused high intensity ultrasound energy for thermal
treatment of the scar tissue, particularly in focal zone 70.
Transducers 200a and 200b are typically activated alternately or
simultaneously to heat the same tissue region. For some
applications, apparatus 100 comprises a single ultrasound
transducer coupled to one of clamping elements 50. Additionally,
the other clamping element may be coupled to an acoustic reflector,
e.g., a mirror with a concave or flat surface, configured to
reflect the energy transmitted from the ultrasound transducer
toward focal zone 70. For some applications, techniques described
with reference to an acoustic reflector in PCT publication WO
2010/029556 to Azhari et al., may be practiced in combination with
techniques described herein.
[0074] Typically, transducers 200a and 200b are configured to
transmit energy through the scar tissue, such that at least a
portion of the transmitted energy reaches the other transducer by
through transmission through the scar tissue. For some
applications, e.g., at predetermined time intervals, one of
transducers may function as a receiver for detecting scattered
waves from the treatment area, in the vicinity of focal zone 70,
while the other transducer continues to apply treatment energy. The
detected waves may be analyzed and used for monitoring changes in
the scar tissue as a result of the treatment process, by measuring
parameters such as scatter intensity, attenuation, speed of sound,
non-linear parameters, sub harmonics and second harmonic
reflections, thus allowing non-invasive monitoring of the treatment
process.
[0075] The following is a proposed, non-limiting, treatment
procedure for application, as appropriate, with the apparatus and
method described herein. Prior to treatment, the scar tissue is
cleaned using 70% isopropyl alcohol wipe and shaved if required.
The area designated for treatment is typically dotted with a pen at
2-3 mm intervals, and an ultrasonic gel is applied to the
designated area. For applications in which the clamping elements
are used, the physician typically clamps the skin containing the
scar tissue such that a portion of the tissue is clamped between
the ultrasound transducers and against a marked dot. The ultrasound
transducers are then activated to apply energy to the tissue as
described hereinabove. Typically, the duration of energy
transmission from the transducers is between 0.1-4 seconds.
Following each treatment, the transducers may be repositioned for
subsequent transmission until the entire designated area has been
treated. Typically, the number of treatments varies, as appropriate
for the size of the scar. Total treatment duration may be, for
example, 30 minutes.
[0076] Reference is made to FIG. 1-4B. Treatments using the
apparatus and methods described herein may include, as appropriate,
causing heating, tissue damage, thermal ablation, mechanical
irritation, cell structure alteration, and/or a cavitation effect.
Typically, the treatment system comprises circuitry for configuring
the applied energy as high intensity focused ultrasound (HIFU),
using techniques known in the art.
[0077] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described hereinabove. Rather, the scope of the present
invention includes both combinations and subcombinations of the
various features described hereinabove, as well as variations and
modifications thereof that are not in the prior art, which would
occur to persons skilled in the art upon reading the foregoing
description.
* * * * *